A typical encryption method will be described below in brief.
Encryption is a technology that ensures the confidentiality of data by intentionally distorting the data at a transmitter and a receiver during communication. In a general encryption procedure, the transmitter encrypts plaintext to ciphertext by use of a predetermined encryption key and transmits the ciphertext to the receiver. The receiver translates the ciphertext into the plaintext by decryption. In this manner, the transmitter and the receiver may encrypt voice packets and/or data packets to ensure the security of communication between them.
There are two types of encryption: symmetric key encryption and asymmetric key encryption.
An encryption scheme that uses the same key for encrypting and decrypting information is called symmetric key encryption. Hence, a symmetric encryption algorithm uses the same key (a shared secret key) for encryption at the transmitter and for decryption at the receiver.
Asymmetric key encryption is an encryption scheme that uses different keys for encryption and decryption, that is, a public key for encryption at the transmitter and a secret key (or private key) for decryption at the receiver. The public key is made public to third parties, whereas the secret key is kept secret between the transmitter and the receiver. For asymmetric key encryption, a public key-based structure or a public key encryption scheme, such as Rivest, Shamir and Adleman (RSA) or the like, may be referred to.
A brief description will be made below of a typical network entry procedure of an MS.
The MS may acquire synchronization to a Base Station (BS) by scanning a downlink channel from the BS. Also, the MS may acquire transmission parameters from an Uplink Channel Descriptor (UCD). Now the MS is able to perform initial ranging with the BS.
After the ranging procedure, the MS may negotiate Subscriber Station (SS) basic capabilities with the BS. The BS may authorize the MS to conduct communication and exchange encryption keys with the MS in an authentication procedure. In this manner, the MS may register to the BS.